The departments of Mechanical Engineering, Material Science &Engineering, and Biological Engineering in the MIT School of Engineering, propose a new Training Grant in Molecular, Cell &Tissue Biomechanics (MCTB). While classical macroscopic biomechanics has traditonally played a central role in medical engineering and physiology, the emerging fields of mechanobiology go further, recognizing the essential connections between forces acting within tissues, cells, and individual molecules, and the fundamental biological processes that regulate growth, development, cell differentiation and migration. Promise now exists not only to explore the role of mechanics in biology, but also to use it advantageously to control cell function in the treatment of disease or in regenerative medicine. An exceptionally exciting opportunity exists at MIT to bring together a group of faculty equally focused on biology and mechanics, emphasizing their intimate integration, within an environment that has embraced these new directions in biomechanics with innovative courses and programs, in support of a unique training experience. Faculty mentors are drawn from, in addition to the three departments mentioned, Biology, Chemical Engineering, and Electrical Engineering &Computer Science, to further broaden the interdisciplinary nature of the program. Funds are requested initially for 4 graduate students, ramping up to 8, each receiving 2 years of support from the TG. Students will apply during their 1st or 2nd years of graduate study at MIT, enabling us to identify only the most qualified candidates based on their MIT coursework and research potential and interests. Although the degree requirements of the departments differ, three core courses will be required of all students in the MCTB Training Program: Molecular, Cell and Tissue Biomechanics, and Fields, Forces and Flows in Biological Systems and a graduate biology course. Close interactions among the Trainees and faculty will be facilitated by a newly initiated Global Enterprise for Molecular and Micro-Mechanics and Molecular Medicine (GEM4), a world-wide consortium for the application of advanced methods in mechanics to medicine and biology that is being launched with the strong support of MIT's top administration. Trainees will also participate in a Summer School on MicroMechanics in Biomedicine, which will be organized annually by GEM4. Faculty members participating in this T32 have active and well-funded research programs in biomechanics at various length scales, from molecular to cell to tissue levels. Students in the Program will have extensive opportunities to learn state- of-the-art technologies to measure, manipulate, and model critical biomechanical phenomena using approaches derived from bioengineering, biophysics, biomaterials science, medicine and biology. Imaging and quantitative analysis are considered essential tools in understanding biomechanical structures.